Rotary jet gun



Ag. 14, 1945. E. N. wAHBURN ROTARY JET GUN Filed July 14, 1941 BY y MTroRN Patented Aug. 14, 1945 ROTARY JET GUN Edward N. Washburn, aruesvme, om., sssiguor to Phillips Petroleum Company, a oorporatiou of Delaware Application July 14, 1941, Serial No. 402,371

(Cl. 16B- 20) 4 Claims.

'I'his invention rrelates to the treatment of underground formations, and more particularly to an apparatus for treating well bores.

In order to facilitate the recovery of hydrocarbon fluids from oil and gas wells, the formations containing the hydrocarbon fluids are often treated with acids or other chemicals. It is cominject a quantity of acid solution into the formation surrounding the well bore, where the acid solution reacts with the formation increasing the size of the pores of the formation, and after the acid has reacted to retrieve the solution oi spent" acid and dissolved chemicals from the formation. Under certain operating conditions it is expedient to impinge the acid solution against the wall of the well bore with great force in order to thoroughly cleanse or break down the formation adjacent to the well bore.

By the practice of my invention I am able to overcome a number of disadvantages which are inherent with present-day types of letting devices or jet guns that are adapted for acidizing well bores. Present-day jetting devices are commonly lowered into a well bore on a string of oil well tubing from the surface of the ground. 'I'hese devices are usually provided with a plurality of jets through which fluid under very high pressure is impinged against the wall of the well bore. As it is a dangerous operation to rotate the tubing string when it is filled with a high pressure fluid, the fluid which is discharged from the jets acts upon only those portions of well bore wall as lie directly in the path of the jets. As I employ a rotating type of jetting device, I am able to .jet fluid on the entire surface of a well bore with the employment of a lesser number of jets than has been heretofore possible. This increases the effectiveness of the jetted fluid. Further, the rotation of my ,letting device is effected without the loss to the jets of any fluids.

The primary object of my invention is to provide an apparatus for treating Well bores.

Another object is to provide a rotatable jetting apparatus for discharging a high velocity fluid against the surface of the well bore.

These and additional objects and advantages will be apparent to persons skilled in the art by reference to the following description and annexed drawing, which pertain to a preferred embodiment of my invention; wherein,

Figure 1 is a central cross-sectional view in elevation showing one half of my invention;

Figure 2 is a view in cross-section taken along line 2--2 of Figure 1; and

Figure 3 is a view in cross-section taken along line-3-3 of Figure 1.

Referring to the drawing and more particularly to Figure 1 for a detailed description of my invention, it will be noted that reference numeral III generally refers to a cylindrical housing which includes an upper hollow cylinderv II, which is preferably internally threaded at the top to connect with a threaded cap I2,` and a lower closed hollow cylindrical member I3, which is provided with a plurality of removal jets I4, connected by threads to a cylinder II. A tubular member I5 is contained within housing I0 in a manner which will be described later along in the speciflcation. Member I5 extends downwardly into the lower portion of the housing. The bottom end of member I5 is adapted to receive a valve housing I6 which is positioned by a threaded ring I1. The valve housing has a valve seat I8 in the top and a plurality of ports I9 in the bottom. A valve head 20, which is connected to a slidable valve stem 2 Il is normally maintained in a closed position by a compression spring 22. Member I5 is also provided with a flange 23 and with a `pair of circular bosses 24 and 25; the cross-section of thebosses is best illustrated in Figures 2 and 3. Bosses 24 and 25 form a part of the nonrotating shaft of a pair of uid motors 26 and 21, respectively, which will be described in detail later along in this speciflcation. The top of member I5 is preferably internally threaded to receive a filter 28, having a plurality of openings 29 which are covered with filtering elements 30. The upper end of the filter is also threaded to receive a string of oil well tubing 3I. It is to be anoted that fluid motor 26 is separated from fluid motor 21 by a sealing ring 32. A second sealing ring 33 is provided at the base of' motor 21. A bearing 34, which is threadedly positioned in the lower end of cylinder II, supports ring 33 and the fluid motors. The inner surface of the bearing journals on member I5 and aligns thev housing with the lower portion of member I5. A suitable bearing 35 is positioned on flange 23 between the external surface of member I5 and the upper inner surface of a positioning ring 36, which is placed between the internal wall of cylinder I I and the periphery of flange 23, maintaining member I5 in a Acentral position. It will be noted that bearing 35 is covered with a sealing ring 31, which is Apositioned on the upper surface of ring 36 and between the internal wall of cylinder II and the external surface of member I5. Sealing ring 31 is held in place by cap I2. Thus, flange 23, positioning ring 36, sealing ring 31 and member I5 provide a race for bearing 35. It will be noted that cap I2 and bearing 34 cooperate to position fluid motors 26 and 21 Within housing II and to place the downward thrust of housing I0 on bearing 35. From the above description of structure,

it is apparent that the motors are mounted in an upper chamber separated. from the lower chamber by bearing 34 and valve 20.

Referring also to Figures 2 and 3 for a descriptlQn Qi the fluid motors, it will be noted that each motor is provided with a hollow cylindrical element 28, which rotates about the circular bosses of member I5. Elements 3B are attached to housing I by a plurality of set screws 39, which insure the rotation of the housing when elements I8 rotate about member I5. Elements 32 are provided with a plurality of radial slots 40, each of which contains a slidable vane 4I. The vanes are provided with suitable springs 42 which urge the vanes inwardly to make contact with member Il. It is to be noted that parts of the fluid motors are in sufficiently close contact to effectively prevent the leakage of fluid. As shown in the drawing, the inner surface of element 38 contacts that portion of member I5 which contains the,

circular bosses. A space 43 is formed between the inner surface of element 3l and the external surface of member I5, where those two surfaces are not in close contact. A suitable inlet 44, which is provided at one side of boss 24 near the upper end of uid motor 28, allows communication between the interior of member I5 and space 43. A suitable outlet 45, which is provided at the other side of boss 24 allows communication between space 43 and a conduit 46 which in turn communicates with the interior of closed cylinder I3. A space 41, identical to space d3, is formed in uid motor 21, which, like motor 2s, has a suitable inlet 48 and an outlet 49 which communicates with-a conduit 50. This conduit allows communication between space d1 and the interior of closed cylinder Il. Conduits i6 and 5d are provided with check valves 5i which prevent fluid from entering the conduits from closed cylinder I3. It is to be further noted that motors 26 and 21 may be identical in size and shape and under certain operating conditions, only one of the motors, such as motor 20, may be used to rotate housing I0. If only one motor is used, the inertia of my apparatus will be utilized to rotate the housing when one of the venes covers the inlet. In order to insure a positive rotation of housing in, I recommend the use of a plurality of fluid motors, which are so arranged and positioned with respect to each other that one of the inlets is always open. I prefer to arrange the bosses so that inlet 36 is forty-five degrees clockwise from inlet i8 with respect to the verticalaxis of member I'c'. Itis to be noted that my arrangement of parts insures a counterclockwise rotation of the fluid motors.

In operation, let us assume that my apparatus has been assembled, as shown in the drawing. Myapparatus is lled with a iiuid, such as an inhibited acid, paraiin solvent, water, or other desired fluid, and is supported by tubing di which conducts fluid thereto. Fluid flows from tubing 3i to filter 28 where entrained solids are removed by' filtering elements 30. Fluid leaves the filter by means of openings 29 and passes into member I5. As valve head 20 is urged against valve seat I8 by a compression spring 22, the fluid in member I5 must be at a higher pressure than that of the closed container in order to move the valve head eff its seat, snowing the fluid 1n member i5 to ow through the valve, ports I9, and into closed cylinder I3. Part of the fluid in member I5 flows through inlets 44 and @38 of fluid motors 26 and 21, respectively, where the uid lls spaces 43 and 41 of the motors and acts upon vanes 4I to cause rotation of housing III in a counterclockwise direction. During the rotation of the housing and elements 3B, the vanes are urged against the external surface of member I5 by springs 42.

As the vanes move along the surfaces of the bosses, they recede fully into slots 4G. As the vanes approach the outlets of the fluid motors,

4 the iiuid which is carried in front of the varies flows through outlets 45 and 49, and is conveyed by conduits 46 and I0. respectively, to closed cylinder I3. Thus, the pressure of the iluid discharged from the fluid motors will be substantially that of the fluid in the closed cylinder. The differential pressure between the uid in member I5 and in the closed cylinder may be small. 'I'he differential pressure is controlled by spring 22 which regulates the movement of valve head 20 with respect to the valve seat. The pressure in the closed cylinder, however, may be very high. Due to the high pressure, the uld emitted from the closed cylinder through iets I4 will have a high velocity and will be capable of producing a high jetting action. When my apparatus is employed in a well bore, it is possible to jet a high velocity fluid along the circumference of the well without rotating tubing 2 I. By employing several jets and by raising or lowering my apparatus in a well bore, I can jet the entire surface of a well bore with a high velocity fluid.

From the foregoing, it is believed that the operation and advantages of the apparatus for practicing my instant invention will be readily comprehended by persons skilled in the art. It is to be clearly understood, however, that various changes in the apparatus shown and described may be resorted to without departing from the spirit of the invention, as defined by the appended claims.

I claim:

1. A well tool of the character described comprising a housing, means dividing said housing into an upper chamber and a lower chamber, fluid conducting means for introducing fluid under pressure into both chambers, a fluid motor in the upper chamber operated by the fluid under pressure therein for rotating said housing, a discharge conduit from said motor opening into the lower chamber, and discharge means in the wall of the part of the housing forming the lower chamber to discharge the fluid therefrom.

2. In the combination of claim l, said conducting means including a spring loaded valve for maintaining a predetermined pressure in the lower chamber.

3. In the combination of claim l, said conducting means including a spring loaded valve for maintaining a predetermined pressure in the lower chamber and a check valve at the discharge end of said conduit to prevent fluid flow from the lower chamber into said conduit.

4. A well tool of the character described comprising fluid conducting means having a port at its end, a spring loaded valve for normally closing said port, a housing rotatably mounted on said conducting means, a sealing partition in said housing dividing it into an upper chamber and a lower chamber, a fluid motor in said upper chamber, said conducting means containing a passage for supplying fluid to said motor, a conduit from said motor discharging into said lower chamber into which said spring loaded valve also discharges, and jet means in the wall of the portion of the housing forming the lower chamber, said spring loaded valve maintaining a predetermined pressure in the lower chamber during discharge of fluid from said jets.

EDWARD N. WASHBURN. 

